Did DDG say they're upranking "good" propaganda and downranking "bad" propaganda? What I understood from the tweets is that DDG is downranking propaganda. Russia happens to produce a lot of it, so they'd be more impacted.
what is and is not propaganda is subjective. something your state government tells you that you take for granted to be true may in fact be propaganda. but in the absence of a Universal Propaganda Detection Algorithm, whether or not something is propaganda is up to personal interpretation.
No, what they said is that they're downranking "sites associated with Russian disinformation", not "propaganda." If what you understood is different than that, it's different that what the tweet directly says.
Source reputation is an important heuristic for determining whether a given piece is content is likely to be spam. If a web property is demonstrated to be routinely publishing falsehoods to sway public opinion, you don't think that should factor into a site's reputation score?